Illegal camcording in digital cinema theatres adversely affects the authorship rights of movie creators and the business of production studios and theatre chains. There are different methods to protect against piracy. Some of the protection schemes are annoying for the audience. Other protections schemes, for example those which are laser-based, are dangerous for the movie viewers or have doubtful efficiency.
A safe and efficient method and apparatus for anti-camcording, which creates enough disturbances on the illegal image to be intrusive and yet does not disturb the quality of digital cinema viewing, would be advantageous. The present invention solves the above-identified problems and is safe and non-intrusive.